1. Field of the Disclosure
The features described herein relate generally to a printhead provided in a printing device which performs printing on a printing medium by discharging liquid therefrom, and a method of manufacturing same.
2. Description of Related Art
A known printhead includes an actuator unit and a flat flexible substrate (FPC) fixed to the actuator unit. The actuator unit includes a piezoelectric layer extending over a number of pressure chambers, and a number of individual electrodes and a number of bumps both provided on a surface of the piezoelectric layer. A number of the individual electrodes are arranged so as to oppose the respective pressure chambers, and are electrically connected to the respective bumps. The FPC is configured to supply drive signals to the actuator unit, and includes a number of lands and a plurality of wirings connected respectively to a number of the lands. The actuator unit and the FPC are fixed to each other by mutual joint between a number of the bumps provided on the actuator unit and a number of the lands provided on the FPC.
The FPC and the actuator unit have different coefficients of thermal expansion. Therefore, for example, the FPC may expand or contract significantly in comparison with the actuator unit due to, for example, variations in working temperature of the printhead or temperature variations in association with natural cooling after a heating step at the time of manufacture. If the expansion or the contraction of the FPC occurs, the contact points between the lands and the bumps, at which the FPC and the actuator unit are fixed to each other, are respectively subject to a force inward or outward of the FPC with respect to the horizontal direction. Accordingly, a stress may concentrate to the contact points between the lands and the bumps to break the contact points.